Switched-mode circuits, including switched-mode power converters and motor controllers, are widely used in power conversion systems of many electronic applications from computers to automobiles. Generally, voltages within a switched-mode power conversion system are generated by performing a DC-DC, DC-AC, and/or AC-DC conversion by operating a switch coupled to an inductor or a transformer. Switched-mode power supplies are usually more efficient than other types of power conversion systems because power conversion is performed by controlled charging and discharging a low loss component, such as an inductor or transformer, therefore reducing energy lost due to power dissipation across resistive voltage drops. Similarly, switched-mode motor controllers may be used to efficiently commutate DC brushless motors with low losses in the driving circuitry.
During operation of a power conversion system, the input voltage supplied to the power conversion system may fluctuate and temporarily drop below a certain voltage threshold, causing a brown-out condition. To protect the power conversion system from the adverse effects caused by the brown-out condition, proper monitoring, control and operation procedures are needed.